This invention relates to methods and apparatus for winding armatures for dynamo-electric machines such as electric motors. The invention is especially advantageous in winding armatures in which the commutator is axially relatively close to the armature core or "stack".
Certain kinds of dynamo-electric machine armatures are required to have the commutator axially close to the armature core. For example, automobile ventilator motors frequently have this type of armature. Because it is difficult or impossible to attach the leads of the armature coils to a commutator which is close to the armature core on which the coils are being wound, it is customary to wind the armature with the commutator at a greater axial spacing from the core. Then, after all the coils have been wound and their leads attached to the commutator, the commutator is shifted to its final position closer to the core. Although workable, this approach has several disadvantages. For example, it is difficult to ensure that the commutator is stable and secure both before and after it is axially shifted. The commutator must not be allowed to rotate during the axial shifting. It may be necessary to provide the armature with a shaft that is longer than is needed in the ultimate use of the armature so that the shaft is long enough to support the commutator in its temporary position during winding of the coils. Shifting the commutator closer to the core after the coil leads have been attached to the commutator produces slack in the coil leads which can be a problem when the armature is rotated at high speed in its ultimate use. Such shifting of the commutator may also weaken the fused connections that have been made between the coil leads and the commutator.
For all of the foregoing reasons it would be desirable to provide methods and apparatus for winding armatures with closely spaced cores and commutators that do not require the commutator to be shifted axially after the coils have been wound, and it is accordingly an object of this invention to provide such methods and apparatus.
It is another object of this invention to provide improved methods and apparatus for winding armatures having closely spaced cores and commutators.